Memory provides data storage for electronic systems. Flash memory is one type of memory, and has numerous uses in modern computers and devices. For instance, modern personal computers may have basic input/output system (BIOS) stored on a flash memory chip. As another example, it is becoming increasingly common for computers and other devices to utilize flash memory in solid state drives to replace conventional hard drives. As yet another example, flash memory is popular in wireless electronic devices because it enables manufacturers to support new communication protocols as they become standardized, and to provide the ability to remotely upgrade the devices for enhanced features.
NOT-AND (NAND) may be a basic architecture of integrated flash memory. A NAND cell unit comprises at least one selecting device coupled in series to a serial combination of memory cells (with the serial combination commonly being referred to as a NAND string). NAND architecture may be configured to comprise vertically-stacked memory cells.
The vertically-stacked memory cells may be block-erased by generating hole carriers beneath them, and then utilizing an electric field to sweep the hole carriers upwardly along the memory cells.
A gating structure of a transistor may be utilized to provide gate-induced drain leakage (GIDL) which generates the holes utilized for block-erase of the memory cells. The transistor may be a select device, such as a source-side select (SGS) device. Difficulties are encountered in utilizing conventional gating structures as select devices. Accordingly, it would be desirable to develop new gating structures, and new methods of forming gating structures.
Gating structures may be utilized in other devices besides select devices, and it would be desirable for new gating structure architectures to be suitable for utilization in other devices besides select devices.